1. Field
The present disclosure relates generally to testing objects and, in particular, to testing the strength of bonds and objects. Still more particularly, the present disclosure relates to a method and apparatus for testing the strength of bonds in a bonded structure using tension waves.
2. Background
A composite object may be comprised of one or more composite structures that are bonded to each other. The composite object is often required to withstand loads that may be encountered during normal or even abnormal use of the composite object. As a result, identifying the strength of bonds in the composite object nondestructively may be required to assess that the composite object is capable of withstanding those forces.
Nondestructive testing or Non-destructive testing (NDT) is a wide group of analysis techniques used in science and industry to evaluate the properties of a material, component or system without causing damage. Because NDT does not permanently alter the article being inspected, it is a highly valuable technique that can save both money and time in product evaluation, troubleshooting and research.
Nondestructive testing of the composite object is more desirable. If the bonds in the composite object meet the desired standard, the composite object remains useable. Nondestructive evaluations are typically selected to fit specific bond material rather than general testing for all parameters. For example, laser bond inspection is a method currently used for nondestructive evaluations of bonds in composite objects. Laser bond inspection tests the strength of bonds between composite structures within a composite object. In this technique, weak bonds may be “pulled apart” by tension waves traveling through the structure. Existing bond inspection devices have multiple draw backs including the fact that they are expensive to construct and operate, and their large footprint makes it difficult to inspect bonds with certain shapes.
Further, inspecting bonds on composite objects such as installed parts on an aircraft may be more difficult than desired because of the size and limited reach of these types of laser bond inspection systems. For example, parts with narrow flanges or angles may preclude placement of the laser bond inspection head in a location to perform the inspection.
Therefore, it would be desirable to have a method and apparatus that takes into account at least some of the issues discussed above, as well as other possible issues.